Add Target Platform for Microsoft Fabric Lakehouse SQL Analytics Endpoint

Please add a new target platform option to support Microsoft Fabric Lakehouse SQL Analytics Endpoints in SQL projects. Currently, there is no explicit target platform for this environment in the vscode-mssql extension or underlying tooling.

While the existing Synapse Serverless target appears to partially work, as noted in [DacFx issue #541](https://github.com/microsoft/DacFx/issues/541), it is not formally supported or optimized for the SQL dialect and constraints of the Fabric Lakehouse SQL endpoint.

**Use Case:**

Developers using Microsoft Fabric need the ability to:

Create and validate T-SQL scripts against the Lakehouse SQL endpoint’s capabilities.

Use DACPAC-based deployments or CI/CD pipelines targeting the Fabric Lakehouse endpoint.

Leverage intellisense and validation tailored to the supported features and syntax.

**Suggested Approach:**

Start from the Synapse Serverless target platform definition, as it is a close approximation.

Apply modifications or restrictions in line with the [documented T-SQL support in Fabric](https://learn.microsoft.com/en-us/fabric/data-engineering/sql-endpoint-overview) (e.g., limitations on certain DDL/DML features, metadata behavior, etc.).

Ensure that the platform ID is recognized by DacFx and SQL project tooling in both VS Code and MSBuild scenarios.

**Benefits:**

Enables a smoother developer experience for Fabric Lakehouse users.

Reduces deployment-time errors by validating compatibility during project builds.

Encourages adoption of Microsoft Fabric by aligning with established development workflows.

see this related issue: Related Issue:

https://github.com/microsoft/DacFx/issues/541

Start by reviewing the existing Synapse Serverless target platform definition and the related DacFx issue #541, then compare them with the documented Fabric Lakehouse SQL endpoint capabilities. Done means a recognized Fabric platform ID works in VS Code and MSBuild scenarios and applies appropriate validation for supported T-SQL features.

Written by the indexing model from the issue text.